Convert an RSA to JsonWebKey format

Program.cs

// nuget package reference with: 
// - System.IdentityModel.Tokens.Jwt
using System;
using System.Security.Cryptography;
using Newtonsoft.Json;
using Microsoft.IdentityModel.Tokens;

static void Main(string[] args) {
  var provider = new RSACryptoServiceProvider(2048);
  var key = new RsaSecurityKey(provider.ExportParameters(true));
  var jwk = JsonWebKeyConverter.ConvertFromRSASecurityKey(key);
  jwk.KeyId = "authentication";
  jwk.Use = "sig";
  jwk.Alg = "RS256";
  var json = JsonConvert.SerializeObject(jwk);
  Console.WriteLine(json);
}

using Microsoft.IdentityModel.Tokens;
using System.Security.Cryptography;
using static System.IdentityModel.Tokens.Jwt.JsonExtensions;

RSA rsa = RSA.Create(2048);
RSAParameters parameters = rsa.ExportParameters(false); // do not export private key
RsaSecurityKey rsaSecurityKey = new(parameters);
JsonWebKey jwk = JsonWebKeyConverter.ConvertFromRSASecurityKey(rsaSecurityKey);

// JsonExtensions.SerializeToJson produces better output than Newtonsoft - because the former can be converted back to JWK:
Console.WriteLine(SerializeToJson(jwk));